Antitheft device



June 2, 1931.

J. R. MIDDLETON ANTITHEFT DEVICE Filed Nov. 12, 1928 Patented June 2, 1931 UNITED STATES JOHN R. MIDDLETON, OF BOISE, IDAHO ANTITHEFT DEVICE Application filed November 12, 1928. Serial No. 318,945.

The present invention relates to anti-theft devices for liquid fuel tanks, and particularly to that type of such devices whereby means are provided for preventing the insertion of a siphon tube in the tank through the filling opening. This particular type of device has the desirable characteristic that, although the ordinary closure cap for the filling opening may be used, nevertheless, even if the 0 cap is removed by an unauthorized person,

the contents of the tank will be entirely inaccessible.

Several embodiments of the invention are shown in the accompanying drawings.

Figure 1 is a vertical section through a tank, and through a device according to the present invention installed in the top wall of the tank.

Figure 2 is a similar section through a tank provided with my improved filling device, the

device here constituting a unit adapted to be fitted to any ordinary tank, and

Figure 3 is a similar view of that of Figure 2, with the exception that here, the tank is provided with a laterally projecting filling neck instead of an opening in the top wall.

Referring to the drawings, and first to Figure 1, 10 represents a tank having a top filling opening in which is set a vertical tubular member 11 with its neck projecting sufficiently above the top wall of the tank to expose threads 11 for engagement by the ordinary closure cap. Member 11 is secured in position in any convenient manner; such as by solderin welding, or the like. The low er portion 0 member 11 is provided with perforations 12, while the inner end is blocked by an imperforate circular disc 13, whose margins extend radially beyond the tubular menr. 0 ber to support at their outer edges a cylindrical shell 14 having imperforate side walls extending upwardly beyond the perforate portion of member 11. Disc 13 and shell 14 may be pressed from a single piece of material to form the cup-like member shown, or they may be separate pieces joined together in any appropriate manner to form a hquid tight joint. The upper edge of the cup-like member, it will be noted, is positioned in spaced relation to the lower side of the tank top, and above the top of this member, tubular member 11 is preferably provided with one or more small air escape openings 12.

As will be obvious, the tank is filled through neck 11, the liquid passing through perforations 12 into the annular chamber bet-ween member 11 and shell 14, these two elements being preferably substantially concentricaL ly disposed. The liquid entering shell 14 flows over the upper edges of the latter into the tank.

It will be seen that it will be absolutely impossible to introduce a siphon tube into the tank through tubular member 11. Even if" such a tube of extremely small cross section could be passed through a perforation 12, it could not be manipulated over the upper edge of shell 14, and down into the lower region of the tank. The air vents 12 are too small to permit the insertion of a tube through them. It follows that with the siphon, it would only be possible to remove the fluid trapped in tubular member 11 and shell 14, and for this reason, these elements are made as small as possible consistent with the free access of hifiuiid into the tank when the latter is being The structure shown in Figure 2 is exactly the same as that in Figure 1, with the exception that here, my improved device is utilized as an accessory, that is, to say, it is not originally built into the tank. The tank 15, according to Figure 2, has a filling neck 16. The cylindrical shell 17 which surrounds the inner tubular member 18 is of such diameter as to readily pass through neck-16 so as to terminate adjacent the lower wall of the tank top. The upper extremity of tubular member 18 is secured to the lower surface of a washer 19, and in alignment with an opening20 in the washer. The lower marginal flanges of washer 19 rest on the top edges of neck 16, and are secured thereto by welding, soldering, or the like. Preferably, the diameter of washer 19 is so chosen, that when it is in position on neck 16, it will not interfere with the engagement of threads 21 by the threads of the usual closure cap. The diameters of the washer and shell are accommodated to the diameter of the filling neck, which, of course, may vary in different tanks. \Vasher 19 may, of course, take the form of a radial fllange integral with member 18.

Tank 22 of Figure 3 is provided with a laterally and upwardly projecting filling neck23. Here, as in Figure 2, a tubular member 24 is secured to the under-surface of a washer 25, whose lower marginal surfaces are supported on the top edges of neck 23. The outer cup-like member 26 is of such size as to be positioned within neck 23 in circumferentially spaced relation to the walls of the latter.

It will be seen that the device is of substantially the same construction in all three figures of the drawings. The only real difference, is that in Figure 1, the top wall of the tank is fitted closely around the central tubular member, while in the other figures a washer-like element is utilized as a fitting member between the walls of a usual filling neck, and the central tubular member. The manner of functioning of the device itself is the same in all instances.

In the claims, I refer to the lower portion of member 11, for example, which is provided with perforations 12, as the perforate portion of that member. This is for the reason that perforations 12, above, serve as influx orifices for the fuel. The language used does not exclude the provision of one or more small air vents in the upper portion of mem- .ber 11, this upper portion, so far as providing influx orifices for the fuel is concerned, being to all intents and purposes, imperforate.

Having thus described my invention, I claim:

1. The combination with a liquid fuel tank having a top filling opening, of a downwardly projecting tubular member set in said opening, the lower portion of said member being provided with perforations, and an imperforate cup-like member surrounding said lower portion, the side walls of said cup-like member extending above the perforate portion of said tubular member in spaced relation thereto.

2. The combination with a liquid fuel tank having a top filling openin of a downwardly projecting tubular member having its upper end fixed in said opening, the lower portion of said member being provided with perforations, and an imperforate cup-like member supported by said tubular member and surrounding the lower portion thereof, the side walls of said cup-like member extending above the perforate portion of said tubular member inspaced relation thereto.

3. The combination with a liquid fuel tank having a top filling opening, of a downwardly projecting tubular member set in said opening, the lower portion of said member being provided with perforations, and an imperforate cup-like member having its bottom wall secured to and blocking the lower end of said tubular member, the sidewalls of said cup-like member extending above the perforate portion of said tubular member in spaced relation thereto.

- 4. The combination with a liquid fuel tank having a top filling opening, of a downwardly projecting tubular member set in said opening, the lower portion of said member being provided with perforations, an imperforate circular disc closing the lower end of said tubular member,'the margins of said disc projecting radially outwardly of the walls of said tubular member, and an imperforate cylindrical shell supported on said disc concentrically with said tubular member and extending upwardly beyond the perforate portion of the latter.

5. The combination with a liquid fuel tank having a filling opening in the top wall thereof, of a filling tube fitted to said opening and 6. The combination with a liquid fuel tank having a filling opening in the top wall thereof, of a filling tube fitted to said opening and projecting downwardly in the tank, the lower portion of said tube being provided with perforations, and an imperforate cup-like member supported by said tube and surrounding the lower portion thereof, the side walls of said cup-like member extending above the perforate portion of said tube in spaced relation thereto and terminating short of the top wall of the tank.

7. The combination with a liquid fuel tank having a filling opening in the top wall thereof of a filling tube fitted to said opening and projecting downwardly in the tank, the lower portion of said tube being provided with perforations, and an imperforate cup-like member having its bottom wall secured to and blocking the lower end of said tubular member, the side walls of said cup-like member extending above the perforate portion of said tubular member in spaced relation thereto and terminating short of the top wall of the tank.

8. The combination with a liquid fuel tank having a filling opening in its top wall, of a filling tube fitted to said opening and projecting downwardly in the tank, the lower portion of said tube being provided with perforations, an imperforate circular disc closing the lower end of said tubular member with its margins projecting outwardly of the walls of the latter, and an imperforate cylindrical shell disposed on said disc concentrically with said tubular member to form an annular chamber between the two, said shell extending above the perforate portion of said tubular member and terminating short of the top wall of said tank.

9. The combination with a closed liquid fuel tank, of an upwardly open chamber within the tank having an imperforate side wall, and a fillin tube extending downwardly into said cham er to discharge liquid therein only at levels below the top of said wall, the liquid passing from the chamber to the tank proper over the top of said wall.

In testimony whereof I have hereunto set my hand.

' J OHNR. MIDDLETON. 

